1. Field of the Invention
The present invention relates to an endoscope apparatus, and in particular to an endoscope apparatus using a communication device capable of performing communication for which DC balance is ensured.
2. Description of the Related Art
Conventionally, an endoscope apparatus has been widely used in a medical field and an industrial field. The endoscope apparatus makes it possible to perform observation, image recording and the like of an endoscopy object site by inserting an endoscope insertion portion of the endoscope apparatus into a body cavity of a patient or an inside of an endoscopy object.
The endoscope apparatus is configured such that it includes the endoscope insertion portion, a processor and a monitor. Image data of an object obtained by picking up an image by an image pickup device provided at a distal end portion of the endoscope insertion portion is transmitted from the endoscope insertion portion to the processor. The processor performs image processing of received image data, generates an endoscopic image and displays the endoscopic image on the monitor. Therefore, an endoscope has an image data transmission device, and the processor has an image data reception device.
In the endoscope apparatus, a signal transmitted from the endoscope is transmitted to the processor via an insulating circuit from the viewpoint of electrical safety. However, since a DC component of the transmitted signal is blocked, it is necessary to ensure DC balance.
For example, as disclosed in Japanese Patent Application Laid-Open Publication No. 2009-111497, code conversion methods, such as the so-called Manchester encoding method and 8B 10B, have been conventionally used as a method for ensuring DC balance.